There are many causes to the error 0xe000031a. To determine the root cause, the failing job must be debugged.
How to debug SharePoint jobs: http://www.symantec.com/docs/TECH37467
V-79-57344-794 - Error: Unable to query the Team database meta-data.
From the SPSWrapper log:
Cannot get property ApplicationPool Object reference not set to an instance of an object.
Cannot get property CurrentIdentityType Object reference not set to an instance of an object.
This issue has been resolved in Backup Exec 2010 R3 hotfix 161390.
Sharepoint 2010 farms that have recently upgraded to Sharepoint 2010 Service Pack 1.